A New Derived and Highly Polymorphic Chromosomal Race of Liolaemus Monticola (Iguanidae) from the 'Norte Chico' of Chile

A multiple Robertsonian fission chromosomal race of the Liolaemus monticola complex in Chile is described and is shown to be the most derived and the most complex among the Liolaemus examined thus far. The 29 karyotyped lizards analysed from the locality of Mina Hierro Viejo, Petorca, Provincia de ValparaUso, Chile, exhibited a diploid chromosomal number ranging from 42 to 44, and several polymorphisms. The polymorphisms included: a pair 1 fission; a pair 2 fission plus a pericentric inversion in one of the fission products, which moved the NOR and satellite from the tip of the long arm of the metacentric 2 to the short arm of the fission product; a fission in pair 3; a polymorphism for an enlarged chromosome pair 6; and a polymorphism for a pericentric inversion in pair 7. This population is fixed for a fission of chromosome pair 4. A total of 76% of the lizards analysed were polymorphic for one or more pairs of chromosomes. We have compared these data with other Liolaemus monticola chromosomal races and calculated the Hardy–Weinberg ratios for the polymorphic chromosome pairs in this Multiple-Fission race. Karyotypic differences between the Northern (2n = 38–40) and the Multiple-Fission (2n = 42–44) races were attributed mainly to Robertsonian fissions, an enlarged chromosome and pericentric inversions involving the macrochromosomes and one microchromosome pair.     

Randomized Controlled Clinical Trial of Blood Glucose Awareness Training (BGAT III) in Switzerland and Germany

Although both diabetes and the efficacy of medical management are international issues, psycho-educational interventions might be culturally bound. Blood Glucose Awareness Training (BGAT) is a psycho-educational program for patients with type 1 diabetes mellitus. It is focused on improving recognition and management of extreme blood glucose levels, and is the best documented American psycho-educational program for this purpose. A randomized controlled clinical trial of BGAT's long-term benefits in a non-American setting has been lacking. One hundred and eleven adults with type 1 diabetes mellitus from Switzerland and Germany participated. After a 6 months baseline assessment, subjects were randomly assigned to receive either 2 months of BGAT (n = 56) or a physician-guided self-help control intervention (n = 55). BGAT improved recognition of low (p = 0.008), high (p = .03), and overall blood glucose (p = 0.001), and reduced frequency of severe hypoglycemia (p = 0.04), without compromising metabolic control. BGAT reduced both the external locus of control (p < 0.02) and fear of hypoglycemia (p < 0.02). BGAT was efficacious in reducing adverse clinical events and achieving clinically desirable goals in a European, as well as American setting.     

Immunological Relationship between the Class I Epitope of Streptococcal M Protein and Myosin

The class I epitope of streptococcal M protein is an epidemiological marker for acute rheumatic fever (ARF)-associated serotypes of group A streptococci and is recognized by anti-M protein monoclonal antibody (MAb) 10B6. Using MAb 10B6, we determined the relationship between the class I epitope of M protein and the α-helical coiled-coil protein myosin. MAb 10B6 reacted by enzyme-linked immunosorbent assay and Western blotting with human cardiac myosin and rabbit skeletal myosin and its heavy meromyosin (HMM) subfragment. Overlapping synthetic peptides of M5 protein were used to identify the region of M5 protein recognized by MAb 10B6. Two C repeat peptides (C2A and C3) containing the amino acid sequence KGLRRDLDASREAK reacted with MAb 10B6. Partial sequence identity, RRDL, was found in the HMM fragment of myosin, which reacted with MAb 10B6. However, not all peptides of M5 protein and myosin containing the RRDL sequence reacted with MAb 10B6. ARF sera and sera from uncomplicated pharyngitis (UNC) reacted with C repeat region peptides of M protein, while acute glomerulonephritis sera were not as reactive. Affinity-purified human antibody to peptide C3 reacted with myosin. The data demonstrate that the class I epitope of M protein is immunologically cross-reactive with myosin and the HMM subfragment, and antibodies to peptide C3 and myosin were present in ARF and UNC sera.Acute rheumatic fever (ARF) is an inflammatory disease that can follow group A streptococcal pharyngitis. The most serious clinical manifestation is rheumatic carditis; however, arthritis, chorea, erythema marginatum, or subcutaneous nodules may be present (40, 41). The pathogenesis of ARF is thought to be mediated by autoimmune mechanisms activated during a streptococcal infection (40). The autoimmune hypothesis is supported by a number of previous observations, including a time interval of at least 3 weeks between the initial streptococcal throat infection and the onset of ARF (40, 41), the identification of heart-reactive immunoglobulin (Ig) and complement deposits in the myocardium of patients with fatal rheumatic carditis (25–27, 30), and the elevation of heart-reactive antibodies in the sera of patients with ARF (46). Cardiac myosin has been identified as one of the cardiac antigens recognized by these heart-reactive antistreptococcal autoantibodies (13, 29).Streptococcal M protein, an α-helical coiled-coil protein, structurally and immunologically mimics host tissue antigens, particularly the rod region of myosin (12, 14, 15, 17, 34, 35). Sequence analysis has revealed that streptococcal M proteins contain blocks of internally repeated amino acid sequences referred to as A, B, and C repeat regions (19). The NH2-terminal nonrepeat and A repeat regions contain determinants of type specificity, while epitopes found in the B and more highly conserved C repeat regions may be common to different M serotypes (19). While there are nearly 100 different serological types of group A streptococcal M protein, epidemiological studies indicate that only a limited number of M protein serotypes are associated with ARF outbreaks (6). This finding suggests that certain M protein serotypes may be more rheumatogenic than others. In a previous attempt to classify streptococcal serotypes according to their rheumatogenic capacity, Widdowson identified human antisera directed to a non-type-specific protein moiety of M protein known as M-associated protein (44, 45). However, a more recent classification scheme has been proposed by Bessen and colleagues, in which streptococcal serotypes were grouped based on the expression of a conserved surface-exposed M protein epitope (4). It was demonstrated that the M serotypes associated with the majority of ARF outbreaks possessed an epitope (class I) defined by monoclonal antibody (MAb) probes 10B6 and 10F5. The sequence of the 10B6 and 10F5 epitope was localized to a 15-amino-acid fragment within the C repeat region of the type 6 M protein (23). The remaining serotypes (class II) lack this epitope or the determinant is structurally inaccessible in those strains. There was a close parallel between serotypes designated class I and those serotypes previously classified as M-associated protein I by Widdowson (44, 45). The fact that only certain serotypes within class I streptococci are rheumatogenic implies that these organisms are of a phenotype that is capable of inducing ARF (4). This implication is supported in part by a recent publication in which it was shown that sera of ARF patients contained high levels of antibodies to the class I epitope, suggesting that their disease was the result of an infection by a class I streptococcus (5).Elevated titers of antibodies to many streptococcal antigens (2), including M protein and the self-antigen myosin (12–15, 17, 29), are associated with ARF. While antibodies to M protein are crucial for the opsonization of streptococci, they have also been implicated in the immunological cross-reactions between streptococci and host tissue antigens such as cardiac myosin (12–15, 17, 29). In earlier studies, many of these cross-reactive epitopes have been localized to the N-terminal, hypervariable A and B repeat regions of the M molecule (12, 15, 17). Myosin-reactive antibodies, found to be elevated in almost all cases of ARF (13), have been shown to bind to human heart tissue and to cross-react with streptococcal M protein (12). Previous studies have demonstrated that immunization of animals with the cell walls of certain strains of group A streptococci resulted in the production of heart-reactive antibodies which could be adsorbed with streptococcal extracts containing streptococcal M protein (16, 24, 28). Human MAbs or myosin affinity-purified antibodies produced from patients with ARF cross-reacted with streptococcal M protein and human cardiac myosin and contributed to the presence of heart-cross-reactive antistreptococcal antibodies in ARF (12, 13, 39). More recent studies have identified cytotoxic antistreptococcal/antimyosin MAbs from rheumatic carditis patients (1). Antimyosin antibody has been shown to deposit in the heart tissues of susceptible mice (31), and a cytotoxic mouse antistreptococcal/antimyosin antibody which binds to the surface of heart cells and to the α-helical coiled coil molecule laminin has been described (10).Identification of myosin cross-reactive epitopes of M protein recognized in ARF has been reported for the amino-terminal half of the molecule (12, 15, 17), and a study by Vashishtha and Fischetti demonstrated antimyosin antibody responses to the C repeat region. However, the reactivity was directed only to denatured myosin (43). More recently, studies of the C repeat or carboxy-terminal region of M protein have shown T-cell cross-reactions with myosin (38). The goal of the present study was to investigate the possibility that the class I epitope in the C repeat region of M protein cross-reacts immunologically with myosin. In this study we show that MAb 10B6, which recognizes the class I epitope of M protein, reacts with cardiac and skeletal myosin. This study also demonstrates that ARF and UNC sera react with a site in the conserved C repeat region of M protein within the class I epitope of rheumatogenic M protein serotypes. The new data show that in addition to previously described N-terminal epitopes, the class I epitope of streptococcal M protein is immunologically cross-reactive with myosin.(Portions of this work were presented at the XIII International Lancefield Society Meeting on Streptococci and Streptococcal Diseases at the Pasteur Institute in Paris, France, in September 1996.)     

Site-directed ELISA with synthetic peptides representing the HIV transmembrane glycoprotein

Two partially overlapping 19 and 22 amino acids long peptides representing a highly immunogenic site of the transmembranous glycoprotein (gp41) of human immunodeficiency virus (HIV) were used as antigen in ELISA tests. The results of antibody determination with this assay were compared with those of three or more conventional ELISAs and Western blot (WB) tests and radioimmunoprecipitation assay. Twenty-six sera from patients with AIDS or LAS and from asymptomatic carriers of HIV infection all showed a pronounced reaction in the peptide ELISA as well as positive results with other tests. In contrast, 27 sera from laboratory workers and blood donors were negative by all tests. A group of 39 blood donor sera, which had shown false positive or ambiguous results in the ELISAs and sometimes in WB tests employed for confirmation, also were negative in all cases with the peptide ELISA. Consecutive samples collected from individuals with primary HIV infection were also analyzed. In 6 out of 9 cases, the peptide ELISA revealed an antibody response within one month after onset of clinical symptoms and sensitivity for antibody detection equaled that of other ELISA tests. Eight sera from five West African persons infected with HIV-related viruses did not react in the peptide ELISA, reflecting differences in properties of the envelope components. The peptide ELISA used in this study appears to represent a simple technique employing chemically synthesized antigen for accurate and sensitive estimation of antibodies to the HIV group of nontransforming human retroviruses.     

Interleukin-4 and interleukin-4 soluble receptor alpha levels in bronchoalveolar lavage from children with asthma.

BACKGROUND: In asthma there is increased expression of the Th2-type cytokine interleukin-4 (IL-4). IL-4 is important in immunoglobulin isotype switching to immunoglobulin E and adhesion of eosinophils to endothelium. OBJECTIVE: We hypothesized that levels of IL-4 in bronchoalveolar lavage (BAL) fluid would be increased in stable, atopic asthmatic children compared with controls and that levels of its physiologic inhibitor IL-4 soluble receptor alpha (IL-4sR alpha) would be correspondingly decreased. METHODS: One hundred sixteen children attending a children's hospital for elective surgery were recruited. A nonbronchoscopic BAL was performed, and IL-4 and IL-4sR alpha were measured in the BAL supernatants. RESULTS: There was no significant difference in IL-4 concentrations between atopic asthmatic children, atopic normal controls, and nonatopic normal controls [0.13 pg/mL (0.13 to 0.87) vs 0.13 pg/mL (0.13 to 0.41) vs 0.13 pg/mL (0.13 to 0.5), P = 0.65]. IL-4sR alpha levels were significantly increased in asthmatic patients compared with atopic controls [6.4 pg/mL (5.0 to 25.5) vs 5.0 pg/mL (5.0 to 9.9), P = 0.018], but not when compared with the nonatopic controls [5.2 pg/mL (5.0 to 10.6), P = 0.19]. CONCLUSIONS: Contrary to expectation, IL-4sR alpha levels are increased in BAL from stable asthmatic children compared with nonatopic controls, and we speculate that IL-4sR alpha is released by inflammatory cells in the airways to limit the proinflammatory effects of IL-4.     

Isolation of human immunodeficiency virus (HIV) from plasma during primary HIV infection

Human immunodeficiency virus (HIV) has been isolated from plasma in 6 of 7 patients showing clinical symptoms of a primary HIV infection. Parallel cultures from peripheral blood mononuclear cells (PBMC) yielded virus in 5 patients. In one case, virus could only be isolated from the cerebrospinal fluid but not from peripheral blood. Detectable viremia was transient and preceded the appearance of HIV specific antibodies. After cessation of acute symptoms, the frequency of HIV isolations was similar to that of asymptomatic carriers (23 and 26%, respectively). The role of the immune response in terminating detectable viremia remains to be established.     

Immunohistochemistry in the diagnosis of malignant mesothelioma

Summary The histological diagnosis of malignant mesothelioma of the pleura, especially the distinction from peripheral adenocarcinoma of the lung, may be difficult. The immunohistochemical reports previously published on this subject show diverging results mainly because a variety of antibodies and staining techniques have been used by the different authors. To obtain comparable and reproducible results standard techniques and commercialized antibodies should be applied in routine pathology. In order to investigate the value of immunohistochemistry for the separation of the two entities formalin fixed and paraffin embedded blocks of 47 mesotheliomas and 22 adenocarcinomas were investigated with the PAP technique and commercially available antibodies to carcino-embryonic antigen (CEA), keratin, vimentin, epithelial membrane antigen (EMA), pregnancy specific antigen (SP₁), S-100 protein and monoclonal antibody lu-5 (mAB lu-5). CEA positivity was found in all 22 adenocarcinomas examined, but only 2/47 (4%) of all mesotheliomas showed a positive result. SP₁ was positive in 13/22 (59%) of the adenocarcinomas, whereas only 3/47 (6%) mesotheliomas were positive for this marker. No significant difference in the rate of positive cases in the adenocarcinoma and mesothelioma group could be found with the other above mentioned antigens. The results of our study indicate that especially CEA, but also SP₁ are valuable markers in the diagnosis of malignant mesothelioma.     

Meeting report

Inflammation Research -     

Developing health science students into integrated health professionals: a practical tool for learning

Background  

An integrated sense of professionalism enables health professionals to draw on relevant knowledge in context and to apply a set of professional responsibilities and ethical principles in the midst of changing work environments [1, 2]. Inculcating professionalism is therefore a critical goal of health professional education. Two multi-professional courses for first year Health Science students at the University of Cape Town, South Africa aim to lay the foundation for becoming an integrated health professional [3]. In these courses a diagram depicting the domains of the integrated health professional is used to focus the content of small group experiential exercises towards an appreciation of professionalism. The diagram serves as an organising framework for conceptualising an emerging professional identity and for directing learning towards the domains of 'self as professional' [4, 5].